有效压力与饱和度变化的气藏多波时移地震AVO响应  

Multi-wave Time Lapse Seismic AVO Responses in Gas Reservoir Vary with Effective Pressure and Saturation

作　　者：侯波 康洪全 程涛 HOU Bo;KANG Hong-quan;CHENG Tao(CNOOC Research Institute Co.,Ltd.,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《CT理论与应用研究（中英文）》2018年第5期601-608,共8页Computerized Tomography Theory and Applications

基　　金："十三五"重大专项课题(西非-南美海域重点区油气地质评价及关键技术研究;2017ZX05032-001)

摘　　要：天然气在开发过程中,储层有效压力和含气饱和度均会发生变化,研究有效压力和含气饱和度的变化对地震响应特征的影响,在基于时移地震的剩余气分布预测研究中具有重要意义。天然气和石油的声学性质有着明显的差异,油藏时移地震的研究成果不能直接应用于气藏,因此需要开展气藏的时移地震研究。利用Shapiro模型表征干岩石弹性模量随有效压力的变化,借助Batzle-Wang方程描述流体速度随压力的变化关系,联合Gassmann理论进行流体替代,表征饱和流体岩石速度随含气饱和度的变化,建立了饱和流体岩石速度随有效压力和饱和度变化的岩石物理模型。基于该模型,对不同含气饱和度和不同有效压力下的气藏储层模型进行了多波时移地震叠前振幅变化(AVO)模拟。结果表明多波时移地震AVO技术可以有效地区分有效压力变化和含气饱和度变化,为进一步开展气藏多波时移地震流体监测提供了理论参考依据。During gas reservoir developing, both reservoir effective pressure and gas saturation vary. It is significant for residual gas distribution predicting, using time-lapse seismic technology, to research on effects of effective pressure variation and gas saturation variation on seismic response characters. Acoustic properties between gas and oil are obviously different, and research results of oil reservoir time lapse seismic cannot be applied to gas reservoir, so it is necessary to develop time lapse seismic research in gas reservoir. Using Shapiro model to characterize dry rock modulus varying with effective pressure, and employing Batzle-Wang equation to describe fluid velocity varying with pressure, and jointing Gassmann theory to implement fluid substitution and describe velocity of fluid saturated rock varying with gas saturation, rock physics model of fluid saturated rock velocity varying with pressure and gas saturation is established. Based on the model, multi-wave time lapse seismic AVO （Amplitude-Variation-with-Offset） responses of gas reservoir model are simulated in different gas saturation and different effective pressure. Results demonstrate that effective pressure and gas saturation can be discriminated by multi-wave time lapse AVO technology and it is a guide to develop multi-wave time lapse seismic fluid monitor.

关 键 词：饱和度 有效压力 时移地震 AVO 多波 

分 类 号：TP631.4[自动化与计算机技术—控制理论与控制工程]